The best part about Constant Contact is that you can try the service before you commit. For 60 days you can toy around with templates and complete services to see if they offer everything you want. Pre-made templates are available that require you to simply choose colors, photos, fonts and fill with your original content. The customer service is great as well.
Mail Chimp can be a completely free service, depending on the size of your email list. Each month the free service offers 12,000 emails to 2,000 contacts. If your list grows larger, you can upgrade to a paid account that charges you monthly. As of 2011, you can expect to pay between $10 and $240. Mail Chimp also provides pre-designed templates or you can upload your own from InDesign.
The future of email marketing lies with iContact. Unlike other services, you must pay to use iContact. However, the services provided with this company stretch further than Constant Contact or Mail Chimp. Currently iContact is developing software that allows you to share your newsletter with your email contacts, but also through social networks like Twitter and Facebook.